What is the moral of dear dumb diary?

this book is about a girl called jamie kelly who has a diary which she wrrites everything in.one day angelines aunty and jamies uncle decide to get married.jamie really doesn't like this because she has to wear an ugly brown dress and clogs and she realizes that she will be related to angeline, jamies worst nightmare and enemy.thhis book is a really good book because its really funny and its easy to read.i would rate this book 8 out of 10 and the age group will probably be 7-12 year olds.